The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

We'll resist GP push from insurers: AMA

Doctors fear private health insurers are making a concerted effort to undermine their profession.

They warn a push by insurers to cover primary care is a step towards a US-style health system.

The insurers are lobbying the federal government to allow them to enter the lucrative primary care market - services which are now covered by Medicare.

Health Minister Peter Dutton has said he is prepared to consider such a change because insurers could deliver savings to the government.

But Australian Medical Association president Brian Owler, in a speech to the National Press Club in Canberra on Wednesday, pointed to a controversial Medibank Private trial in Queensland where its members were being given priority in a small number of clinics.

"Those without insurance ... will have less access to a GP," he said.

"I fear a concerted effort on behalf of private health insurers to undermine and control the medical profession."